Skip starting WearableSensingService in Wear

This service has been documented to not be supported on Wear, but has
been running on Wear devices. We are now avoiding the start of the
service on Wear devices.

CTS tests already have been skipped for Wear devices (see ag/26350608).

Bug: 340929916
Test: atest WearableSensingManagerTest CtsWearableSensingServiceDeviceTest WearableSensingManagerIsolatedServiceTest HotwordDetectionServiceBasicTest
Change-Id: I6bb4abcfe72dfed3bc23e63b320a48bf07fb9f40